With development of display technologies, curved surface display devices have become popular and appeared in consumption market. A curved surface screen bending inwards is more adapted to the physiological structure of a human's eye ball, and a depth of field generated by bending the screen makes a picture richer in level and detail and more real, so that a viewer may feel like he is in the picture. The curved surface screen may effectively reduce a difference between a distance from a picture at a side edge of the screen to the viewer's eye and a distance from a picture at a central part of the screen to the viewer's eye, so that an even more uniform image can be obtained and a range of view may be increased.
Curvature of a curved surface display device may need to be adjusted in some certain occasions, for example, if there are relatively too much viewers, some viewers at positions away from a center or a central vertical axis of the curved surface will have an asymmetrical viewing angle, which leads to a decreased viewing effect. In this case, curvature of the display panel needs to be decreased, or the display panel may even need to be restored to a flat state, so as to ensure a good viewing effect.
In existing technologies, a curved surface display device having an adjustable curvature is usually provided with an adjusting mechanism mounted to its back plate for adjusting the curvature of the display panel. The adjusting mechanism may apply forces at both ends of the back plate to bend the back plate, and the curvature of the backplate may be changed by adjusting values of the forces applied by the adjusting mechanism, so that the display panel is bent and deformed by the back plate, and adjustment of curvature of the display panel is achieved.
Usually, the adjusting mechanism also functions to maintain the bent shape of the display panel after the curvature of the display panel is adjusted. However, due to deformation characteristics of the back plate and the display panel and other factors, the curved shape of the back plate and the display panel maintained by the adjusting mechanism is not consistent with a curved shape that is suitable for watching, and viewing effect is thereby reduced.